JBJS | Current Trends in the Management of Adamantinoma of Long Bones : An International Study*

The Journal of Bone & Joint Surgery, Volume 82, Issue 8

Articles | August 01, 2000

Current Trends in the Management of Adamantinoma of Long Bones : An International Study*

Abid A. Qureshi, M.D.†; Susan Shott, Ph.D.†; Bruce A. Mallin, M.D.‡; Steven Gitelis, M.D.†

Investigation performed at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois
*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.
†Section of Orthopedic Oncology (S. G.), Department of Orthopedic Surgery (A. A. Q.), and Biostatistics Unit, Department of Neurosurgery (S. S.), Rush-Presbyterian-St. Luke's Medical Center, 1725 West Harrison Street, Suite 440, Chicago, Illinois 60612-3824.
‡Department of Orthopaedic Surgery, Ortho Care International, 525 North 18th Street, Suite 605, Phoenix, Arizona 85006.

The Journal of Bone & Joint Surgery. 2000; 82:1122-1122

5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

text A A A

Abstract

Background: Adamantinoma of long bones is a rare tumor. Published reviews of the orthopaedic management of adamantinoma have involved limited follow-up of small numbers of patients. The oncological aggressiveness of this tumor is unknown. Limb salvage is currently the treatment of choice for most adamantinomas. The purpose of this study was to evaluate the characteristics of adamantinoma of long bones as well as the oncological outcome and the complications of limb salvage operations.

Methods: A retrospective study was designed to evaluate the clinical outcomes of limb salvage operations for the treatment of adamantinoma. Data on seventy biopsy-proven cases of adamantinoma treated between 1982 and 1992 at twenty-three different cancer centers in Europe and North America were obtained.

Results: The median duration of follow-up was 7.0 years. The male:female ratio was 3:2, and the mean age was thirty-one years. Limb salvage was attempted in 91 percent (sixty-four) of the seventy patients, and the final rate of limb preservation was 84 percent (fifty-nine of seventy). Wide operative margins were obtained in 92 percent (fifty-eight) of sixty-three patients. An intercalary allograft was used to reconstruct the segmental bone defect in 51 percent (thirty-six) of the seventy patients. Reconstruction-related complications occurred in 48 percent (thirty) of sixty-two patients. Nonunion and fracture were the most common complications, occurring in 24 percent (fifteen) and 23 percent (fourteen) of sixty-two patients, respectively. Kaplan-Meier analysis demonstrated a rate of local recurrence of 18.6 percent at ten years. Wide operative margins were associated with a lower rate of local recurrence than marginal or intralesional margins were (p < 0.00005). Kaplan-Meier analysis showed a survival rate of 87.2 percent at ten years. There were no significant relationships between survival and the stage of the tumor (p = 0.058), duration of symptoms (p = 0.90), gender (p = 0.79), or wide operative margins (p = 0.14).

Conclusions: Current treatment of adamantinoma, including en bloc tumor resection with wide operative margins and limb salvage, provides lower rates of local recurrence than has been previously reported. In the present study, the limb preservation rate was 84 percent (fifty-nine of seventy), and the survival rate was 87.2 percent at ten years. The rate of complications related to the limb reconstruction was high.

Figures in this Article

Introduction

Introduction | Materials and Methods | Results | Discussion | References

Adamantinoma of long bones is a rare primary malignant bone tumor of disputed histogenesis. Epithelial cells^{7,8,13,20,21,32,38,39,49}, endothelial cells^5,9,18,24, as well as synovial cells^17,22,23 have been implicated as the cells of origin. Recently, investigators have attempted to define the histogenesis of these tumors using molecular and cytogenetic techniques^{2,15,16,27,41}, but they have been unable to identify a consistent, nonrandom cytogenetic aberration. Schajowicz et al.⁴⁰ defined adamantinoma as a malignant, or at least locally malignant, tumor characterized by a wide range of morphological patterns, the most common of which consists of circumscribed masses or tubular formations of what appear to be epithelial cells surrounded by spindle-celled fibrous tissue.

It has been estimated that adamantinomas of long bones account for less than 1 percent of primary malignant bone tumors⁴⁵. Unni et al.⁴⁵ reported twenty-nine cases in an analysis of 5000 primary malignant bone tumors in 1974, Huvos and Marcove¹⁸ reported fourteen cases in 1975, Moon and Mori³¹ performed a meta-analysis of 200 cases in 1986, Czerniak et al.⁷ reported twenty-five cases in 1989, Keeney et al.²⁰ reported eighty-five cases in 1989, Campanacci⁴ reported fourteen cases in 1990, and Hazelbag et al.¹⁴ reported thirty-two cases in 1994. All of these studies, as well as others^3,48, emphasized the ongoing debate about the pathogenesis of this neoplasm.

Adamantinomas are slow-growing tumors with a limited propensity for metastasis and local recurrence, which usually renders them amenable to curative operative resection. There has been limited experience with the use of chemotherapeutic agents²⁵ and radiation for adamantinoma. This paper reviews current trends in the management of these tumors and presents an analysis of oncological outcomes and complications.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1:: Figs. 1-A through 1-H: A patient with a mid-diaphyseal biopsy-proved adamantinoma of the tibia.
Fig. 1-A: Anteroposterior radiograph showing the lesion. Note the well defined margins with lytic and sclerotic areas.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-B: Lateral radiograph showing cortical involvement.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-C:: Computed axial tomography image through the lesion, showing the intracompartmental nature of the tumor.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-D:: Coronal T2-weighted magnetic resonance image through the lesion, showing high signal intensity.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-E:: Plain radiograph and photograph of the specimen after en bloc excision.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-F:: Photomicrograph of a section of the lesion, showing the spindle-cell and epithelial components coexisting side by side. There is relatively little pleomorphism (hematoxylin and eosin, Â¥ 250).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-G:: Anteroposterior and lateral radiographs of the tibia, made five years after reconstruction with an intercalary allograft. Note the complete incorporation of the allograft at the allograft-host bone junction.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-H:: Anteroposterior and lateral radiographs of the tibia, made five years after reconstruction with an intercalary allograft. Note the complete incorporation of the allograft at the allograft-host bone junction.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2-A:: Figs. 2-A, 2-B, and 2-C: A patient with a biopsy-proved adamantinoma involving the entire tibial diaphysis.
Fig. 2-A: Anteroposterior radiograph showing the lesion.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2-B: Lateral radiograph showing extensive cortical and medullary involvement.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2-C: Radiograph made five years after en bloc tumor resection followed by reconstruction with use of a vascularized graft from the contralateral fibula.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3-A: Anteroposterior radiograph made after en bloc resection of an adamantinoma followed by reconstruction with use of a vascularized graft from the contralateral fibula. Note that an external fixator was used to stabilize this construct.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3-B: Anteroposterior radiograph made after removal of the external fixator. Note the union at the proximal and distal graft sites.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 4:: Kaplan-Meier curve showing the proportion of patients with local recurrence (y axis) versus the months from surgery to local recurrence (x axis).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 5:: Kaplan-Meier curves showing the proportion of patients with wide excision and those with marginal or intralesional excision (y axis) versus the months from surgery to local recurrence (x axis).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 6:: Kaplan-Meier curve showing the proportion of surviving patients (y axis) versus the years from diagnosis to death or last follow-up (x axis).

View Larger

Table I: Demographic and Clinical Characteristics of Patients with Adamantinoma of a Long Bone

Variable
Age at diagnosis (n = 69) (yrs.)
Mean and standard deviation	31.3 17.6
Median (range)	29 (7-86)
Female gender (n = 70) (no. of patients)	28 (40%)
Prior biopsy (n = 53) (no. of patients)	36 (68%)
Prior diagnosis (n = 67) (no. of patients)
None	41 (61%)
Fibrous dysplasia	9 (13%)
Ossifying fibroma	6 (9%)
Osteofibrous dysplasia	3 (4%)
Epithelioid neoplasm	1 (1%)
Squamous-cell carcinoma	1 (1%)
Spindle-cell carcinoma	1 (1%)
Metastatic adenocarcinoma	1 (1%)
Nonossifying fibroma	1 (1%)
Aneurysmal bone cyst	1 (1%)
Osteomyelitis	1 (1%)
Campanacci disease	1 (1%)
Duration of symptoms (n = 60) (mos.)
Mean and standard deviation	62.5 96.0
Median (range)	24 (0.5-444)
Pathological fracture (n = 70) (no. of patients)	17 (24%)
Tumor site (n = 70) (no. of patients)
Tibia	60 (86%)
Fibula	3 (4%)
Tibia and fibula	4 (6%)
Femur	1 (1%)
Ulna	1 (1%)
Radius	1 (1%)
Enneking stage¹⁰ (n = 69) (no. of patients)
IA	35 (51%)
IB	32 (46%)
III	2 (3%)

Add to My JBJS

Table I: Demographic and Clinical Characteristics of Patients with Adamantinoma of a Long Bone

Variable
Age at diagnosis (n = 69) (yrs.)
Mean and standard deviation	31.3 17.6
Median (range)	29 (7-86)
Female gender (n = 70) (no. of patients)	28 (40%)
Prior biopsy (n = 53) (no. of patients)	36 (68%)
Prior diagnosis (n = 67) (no. of patients)
None	41 (61%)
Fibrous dysplasia	9 (13%)
Ossifying fibroma	6 (9%)
Osteofibrous dysplasia	3 (4%)
Epithelioid neoplasm	1 (1%)
Squamous-cell carcinoma	1 (1%)
Spindle-cell carcinoma	1 (1%)
Metastatic adenocarcinoma	1 (1%)
Nonossifying fibroma	1 (1%)
Aneurysmal bone cyst	1 (1%)
Osteomyelitis	1 (1%)
Campanacci disease	1 (1%)
Duration of symptoms (n = 60) (mos.)
Mean and standard deviation	62.5 96.0
Median (range)	24 (0.5-444)
Pathological fracture (n = 70) (no. of patients)	17 (24%)
Tumor site (n = 70) (no. of patients)
Tibia	60 (86%)
Fibula	3 (4%)
Tibia and fibula	4 (6%)
Femur	1 (1%)
Ulna	1 (1%)
Radius	1 (1%)
Enneking stage¹⁰ (n = 69) (no. of patients)
IA	35 (51%)
IB	32 (46%)
III	2 (3%)

View Larger

Table II: Treatment of Patients with Adamantinoma of a Long Bone

Variable
Biopsy type (n = 69) (no. of patients)
Open incisional	42 (61%)
Open excisional	25 (36%)
Open incisional and closed needle	1 (1%)
Closed needle	1 (1%)
Treatment of tumor (n = 70) (no. of patients)
Initial amputation	6 (9%)
Limb salvage not followed by amputation	59 (84%)
Limb salvage followed by amputation	5 (7%)
Limb salvage type (n = 64) (no. of patients)
En bloc resection	61 (95%)
Intralesional excision	3 (5%)
Amount of bone resected (n = 48) (cm)
Mean and standard deviation	15.3 6.5
Median (range)	14.2 (5-32)
Wide surgical margins (n = 63) (no. of patients)	58 (92%)
Reconstruction type (n = 64) (no. of patients)
Nonvascularized autogenous	19 (30%)
Vascularized fibular	16 (25%)
Allograft	39 (61%)
Ankle arthrodesis (n = 64) (no. of patients)	3 (5%)
Adjuvant treatment (n = 70) (no. of patients)
None	65 (93%)
Radiation only	2 (3%)
Chemotherapy only	2 (3%)
Radiation and chemotherapy	1 (1%)

Add to My JBJS

Table II: Treatment of Patients with Adamantinoma of a Long Bone

Variable
Biopsy type (n = 69) (no. of patients)
Open incisional	42 (61%)
Open excisional	25 (36%)
Open incisional and closed needle	1 (1%)
Closed needle	1 (1%)
Treatment of tumor (n = 70) (no. of patients)
Initial amputation	6 (9%)
Limb salvage not followed by amputation	59 (84%)
Limb salvage followed by amputation	5 (7%)
Limb salvage type (n = 64) (no. of patients)
En bloc resection	61 (95%)
Intralesional excision	3 (5%)
Amount of bone resected (n = 48) (cm)
Mean and standard deviation	15.3 6.5
Median (range)	14.2 (5-32)
Wide surgical margins (n = 63) (no. of patients)	58 (92%)
Reconstruction type (n = 64) (no. of patients)
Nonvascularized autogenous	19 (30%)
Vascularized fibular	16 (25%)
Allograft	39 (61%)
Ankle arthrodesis (n = 64) (no. of patients)	3 (5%)
Adjuvant treatment (n = 70) (no. of patients)
None	65 (93%)
Radiation only	2 (3%)
Chemotherapy only	2 (3%)
Radiation and chemotherapy	1 (1%)

View Larger

Table III: Reconstruction-Related Complications in Patients with Adamantinoma of a Long Bone*

*The sum of the sample sizes for the different types of reconstruction is greater than seventy because more than one type was used for some patients.

Complication	No. of Patients
All reconstructions (n = 62)
None	32 (52%)
Nonunion	15 (24%)
Fracture	14 (23%)
Infection	6 (10%)
Soft-tissue complication	2 (3%)
Delayed union	2 (3%)
Other	7 (11%)
Reconstructions with allograft (n = 38)
None	20 (53%)
Nonunion	6 (16%)
Fracture	8 (21%)
Infection	2 (5%)
Soft-tissue complication	1 (3%)
Delayed union	1 (3%)
Other	6 (16%)
Reconstructions with vascularized fibular graft (n = 16)
None	8 (50%)
Nonunion	5 (31%)
Fracture	3 (19%)
Infection	3 (19%)
Soft-tissue complication	1 (6%)
Delayed union	0 (0%)
Other	2 (13%)
Reconstructions with nonvascularized autograft (n = 19)
None	11 (58%)
Nonunion	5 (26%)
Fracture	3 (16%)
Infection	4 (21%)
Soft-tissue complication	2 (11%)
Delayed union	0 (0%)
Other	2 (11%)

Add to My JBJS

Table III: Reconstruction-Related Complications in Patients with Adamantinoma of a Long Bone*

*The sum of the sample sizes for the different types of reconstruction is greater than seventy because more than one type was used for some patients.

Complication	No. of Patients
All reconstructions (n = 62)
None	32 (52%)
Nonunion	15 (24%)
Fracture	14 (23%)
Infection	6 (10%)
Soft-tissue complication	2 (3%)
Delayed union	2 (3%)
Other	7 (11%)
Reconstructions with allograft (n = 38)
None	20 (53%)
Nonunion	6 (16%)
Fracture	8 (21%)
Infection	2 (5%)
Soft-tissue complication	1 (3%)
Delayed union	1 (3%)
Other	6 (16%)
Reconstructions with vascularized fibular graft (n = 16)
None	8 (50%)
Nonunion	5 (31%)
Fracture	3 (19%)
Infection	3 (19%)
Soft-tissue complication	1 (6%)
Delayed union	0 (0%)
Other	2 (13%)
Reconstructions with nonvascularized autograft (n = 19)
None	11 (58%)
Nonunion	5 (26%)
Fracture	3 (16%)
Infection	4 (21%)
Soft-tissue complication	2 (11%)
Delayed union	0 (0%)
Other	2 (11%)

Materials and Methods

Introduction | Materials and Methods | Results | Discussion | References

We conducted a multicenter study of biopsy-proven cases of adamantinoma of long bones that had been evaluated and treated between 1982 and 1992 in North America and Europe. Surgeons were asked to complete a questionnaire concerning demographic data, location of the tumor, duration of the symptoms, preexisting conditions (such as fibrous dysplasia, ossifying fibroma, and osteofibrous dysplasia), radiographic dimensions of the tumor, type of biopsy, stage of the tumor as classified with the system of Enneking et al.¹⁰, type of operative treatment (limb salvage or amputation), type of reconstruction, operative complications, adjuvant treatment, and prevalence of local recurrence, metastasis, and survival. History of trauma was not included in the questionnaire. Margins were defined in the questionnaire as marginal en bloc resection of the tumor or as wide en bloc resection of the tumor with surrounding normal tissue. Questionnaires were sent to fifty cancer centers in North America and Europe. Thirty surgeons at twenty-three institutions (twenty in the United States, two in Canada, and one in Italy) contributed cases that met the selection criteria. Data for a total of seventy patients were obtained from these questionnaires. No data were collected regarding functional outcomes.

Association between nominal variables was evaluated with the chi-square test of association. Kaplan-Meier plots were used to obtain survival, local-recurrence, and metastasis curves and rates. The log-rank test and Cox proportional-hazards regression were performed to investigate variables related to survival and recurrence. A 0.05 significance level was used for all statistical tests.

Results

Introduction | Materials and Methods | Results | Discussion | References

The median duration of follow-up of the patients who did not die during the follow-up period was 7.0 years (range, 1.1 to 15.7 years). The demographic and clinical characteristics of the patient population are summarized in Table I. The male:female ratio was 3:2. The mean duration of symptoms was 62.5 months. The tibia, which was involved in sixty (86 percent) of the seventy patients, was the most common site of the tumors. According to the system of Enneking et al.¹⁰, the tumors were almost evenly split between stages IA and IB, with only two stage-III cases.

Tables II and III summarize the modalities of treatment and the complications related to the reconstructive procedure in these patients. Limb salvage was attempted in 91 percent (sixty-four) of the seventy patients (Fig. 1-A, Fig. 1-B, Fig. 1-C, Fig. 1-D, Fig. 1-E, Fig. 1-F Fig. 1-G, and Fig. 1-H). Of these sixty-four patients, 8 percent (five) later required amputation; thus, the final rate of limb salvage was 84 percent (fifty-nine of seventy). En bloc resection was carried out in nearly all (95 percent [sixty-one]) of the sixty-four limb-salvage procedures, and wide operative margins were obtained in 92 percent (fifty-eight) of sixty-three patients. Reconstruction with an allograft was used in 61 percent (thirty-nine) of sixty-four patients, and an intercalary allograft was used in 92 percent (thirty-six) of the thirty-nine. Two patients were treated with an osteoarticular allograft, and one was treated with morselized allograft. Plates and screws were used to secure the intercalary allograft in 63 percent (twenty-two) of thirty-five patients, and locked intramedullary nails were used in 11 percent (four) of thirty-five. A vascularized fibular autograft was used for reconstruction of the extremity in 25 percent (sixteen) of sixty-four patients (Fig. 2-A, Fig. 2-B, and Fig. 2-C). Ipsilateral and contralateral fibulae were harvested with equal frequency (eight cases each). Plates and screws were used to secure the vascularized fibular graft in six patients; screws alone, in five; an external fixator, in four (Fig. 3-A and Fig. 3-B); and an unspecified method, in one. No differences were noted in the efficacy of one fixation technique compared with that of the others. Only 7 percent (five) of the seventy patients received adjuvant treatment.

Forty-eight percent (thirty) of sixty-two patients had some type of reconstruction-related complication. Nonunion and fracture were the most common complications, occurring in 24 percent (fifteen) and 23 percent (fourteen) of sixty-two patients, respectively. Nonunion, fracture, and infection were not significantly related to gender, use of a vascularized fibular autograft, or use of an allograft. Nonunion occurred more frequently in patients with a stage-IA tumor¹⁰ than in those with a stage-IB tumor (35 percent [twelve of thirty-four] compared with 4 percent [one of twenty-six]; p = 0.003). No significant relationships were found between the stage of the tumor and the occurrence of a fracture or infection. Infection occurred more frequently when a nonvascularized autogenous bone graft had been used (21 percent [four of nineteen] compared with 5 percent [two of forty-three]; p = 0.044). No significant relationships were found between the use of a nonvascularized autogenous bone graft and the occurrence of a nonunion or fracture.

The rates of local recurrence were 8.6 percent at five years and 18.6 percent at ten years according to the Kaplan-Meier method (Fig. 4). There were no significant relationships between local recurrence and stage¹⁰ (p = 0.060), duration of symptoms (p = 0.92), gender (p = 0.058), age (p = 0.36), type of biopsy (open incisional compared with open excisional) (p = 0.84), use of a nonvascularized autogenous bone graft (p = 0.17), use of a vascularized fibular graft (p = 0.089), or use of an allograft (p = 0.36). Patients who had wide operative margins had a significantly lower prevalence of local recurrence than those who had less-than-wide margins (p < 0.00005) (Fig. 5).

Metastasis was present at the time of the operation in two patients, and it occurred after the operation in seven (10 percent) of the other sixty-seven patients for whom data with regard to metastasis were available. The date of the metastasis was unknown for four patients.

Kaplan-Meier analysis demonstrated five-year and ten-year survival rates of 95.5 and 87.2 percent (Fig. 6). No significant relationships were found between survival and stage¹⁰ (p = 0.058), duration of symptoms (p = 0.90), gender (p = 0.79), biopsy type (open incisional compared with open excisional) (p = 0.061), wide operative margins (p = 0.14), use of a nonvascularized autogenous bone graft (p = 0.62), use of a vascularized fibular graft (p = 0.24), or use of an allograft (p = 0.072). As expected, the rate of survival decreased as age increased (p = 0.0085). At the time of the most recent follow-up, 6 percent (four) of the seventy patients had died of disease, 88 percent (sixty-one) of sixty-nine had no evidence of disease, and 6 percent (four) of sixty-nine were alive with disease.

Discussion

Introduction | Materials and Methods | Results | Discussion | References

Adamantinomas are rare. Operative removal is the treatment of choice. Most previous studies of these tumors have been from single institutions and have spanned long periods of time, leaving unresolved the issue of which operative procedure is the most safe and effective for the management of these tumors in the rapidly evolving field of orthopaedic oncology. Interestingly, owing to the rarity of adamantinoma, some of the largest studies have been carried out over thirty-nine to eighty-year periods^14,18,20, during which newer treatment modalities and staging systems were developed; this made the older studies difficult to compare with the more recent studies. The present study was designed by the Musculoskeletal Tumor Society to describe and assess the present management of adamantinoma of long bones. The demographic characteristics of the patients in this study were comparable with those of subjects in previous reports^14,20,31. However, the 23 percent prevalence of pathological fracture was higher than the 10 percent rate reported in the past^19,42,46, even though physicians were not asked specifically about this presenting sign. The relationship of adamantinoma to osteofibrous dysplasia and other preexisting mesenchymal lesions is currently controversial. The present study was not intended to examine this relationship.

Adamantinoma is highly radioresistant⁴⁸, and chemotherapy has not been shown to be effective¹⁴. Operative treatment includes amputation^1,18,31 and, more recently, en bloc resection with wide margins and limb salvage^3,11,37,45. The final limb-salvage rate was 84 percent (fifty-nine of seventy patients) in the present series. The rate of local recurrence was 18.6 percent, which was lower than the previously reported rates of 31 percent (twenty-six of eighty-five patients)²⁰ and 32 percent (nine of twenty-eight patients)¹⁴. As expected, wide operative margins were associated with a significantly lower risk of local recurrence. Contrary to the findings in previous studies^14,20, there were no significant relationships between local recurrence and gender or duration of symptoms in the current series.

Limb reconstruction after en bloc tumor resection is an integral part of a limb salvage operation. Different reconstruction options include allografts, vascularized and nonvascularized autografts, metallic segmental implants, and distraction osteogenesis. Allografts have long been used to restore bone stock^{11,12,26,28,30,33-36}. Intercalary reconstruction appears to be the most successful method. Complications associated with its use include infection, fracture, and nonunion, with reported rates of 12 percent (twelve), 17 percent (eighteen), and 29 percent (thirty) of 104 patients, respectively³³. However, there is no consensus in the literature regarding which form of fixation is superior. Vascularized fibular grafts have been considered the best type of graft for large segmental bone defects in some series^44,47. Metallic segmental implants have a shorter life span^6,43. Allografts were used in 61 percent (thirty-nine) of the sixty-four reconstructions in the present series, and the majority were intercalary reconstructions secured with plates and screws. However, no differences in the efficacy of different fixation techniques were noted. Complications related to the reconstruction occurred in 48 percent of the patients, with nonunion and fracture being the most common (occurring in 24 and 23 percent of the patients, respectively). The frequencies of these complications, although comparable with those previously reported³³, remain unacceptably high.

The ten-year survival rate in this series was 87.2 percent. At the time of the most recent follow-up, 88 percent (sixty-one) of sixty-nine patients had no evidence of disease, 6 percent (four) of sixty-nine were alive with disease, and 6 percent (four) of seventy had died of disease. Mortality rates of 13 percent (eleven of eighty-five patients)²⁰ to 18 percent (thirty-six of 200 patients)³¹ have been previously reported. Interestingly, there were no significant relationships between survival and the stage¹⁰ of the tumor or wide operative margins in our series. These findings may be attributable to the sample size. The rates of metastasis reported in the literature are approximately 15 to 30 percent^14,20,29,31. In the present series, the metastasis rate after the operation was 10 percent.

The current management of adamantinoma of long bones with modern operative techniques, including en bloc resection, wide operative margins, and limb salvage, may provide a lower rate of local recurrence than previous methods. However, the possible effect of these treatment modalities on long-term survival remains unclear. In addition, possible differences in the efficacy of various reconstruction methods remain unknown.

Note: The Massachusetts General Hospital and Boston Children's Hospital contributed fourteen cases to this study (contributing surgeons: Henry J. Mankin, M.D. [five cases], Mark C. Gebhardt, M.D. [five], and Dempsey S. Springfield, M.D. [four]). The Mayo Clinic contributed thirteen cases (contributing surgeons: Douglas J. Pritchard, M.D. [eight cases], Thomas C. Shives, M.D. [three], Michael G. Rock, M.D. [one], and Franklin H. Sim, M.D. [one]). The Rizzoli Institute (Mario Campanacci, M.D., and R. Capanna, M.D.) contributed ten cases. The University of Chicago (Michael A. Simon, M.D.) contributed four cases. Memorial Sloan-Kettering contributed four cases (contributing surgeons: Ralph C. Marcove, M.D. [one case], Joseph M. Lane, M.D. [two], and John H. Healey, M.D. [one]). The University of Florida (Dempsey S. Springfield, M.D.) and Ohio State University (Lawrence D. Weis, M.D.) contributed three cases each. Hahnemann Medical School (Richard D. Lachman, M.D.), Columbia-Presbyterian Medical Center (Harold M. Dick, M.D.), Vanderbilt University (Herbert Schwartz, M.D.), and Rush Medical School (Steven Gitelis, M.D) contributed two cases each. Foothills Medical Center (Norman S. Schachar, M.D.), Maisonneuve-Rosemont Hospital (Robert E. Turcotte, M.D.), Medical Center East (William K. Dunham, M.D., and Kenneth A. Jaffe, M.D.), Presbyterian University Hospital (Mark A. Goodman, M.D.), University of Nebraska (James R. Neff, M.D.), St. Thomas Medical Center (Mark C. Leeson, M.D.), University of North Carolina (Gary D. Bos, M.D.), Denver Orthopaedic Clinic (Ross M. Wilkins, M.D.), Cancer Institute, Sinai Hospital (Alan M. Levine, M.D.), Dallas Sarcoma Group (Gerhard E. Maale, M.D.), and University of South Carolina (John L. Eady, M.D.) contributed one case each.

References

Introduction | Materials and Methods | Results | Discussion | References

Baker, P. L.; Dockerty, M. B.; and Coventry, M. B.: Adamantinoma (so-called) of the long bones. Review of the literature and a report of three new cases. J. Bone and Joint Surg.,36-A: 704-720, July 1954.36-A704 1954

Bridge, J. A.; Dembinski, A.; DeBoer, J.; Travis, J.; and Neff, J. R.: Clonal chromosomal abnormalities in osteofibrous dysplasia. Implications for histopathogenesis and its relationship with adamantinoma. Cancer,,73: 1746-1752, 1994.731746 1994

Campanacci, M.; Giunti, A.; Bertoni, F.; Laus, M.; and Gitelis, S.: Adamantinoma of the long bones. The experience at the Istituto Ortopedico Rizzoli. Am. J. Surg. Pathol.,5: 533-542, 1981.5533 1981 [PubMed]

Campanacci, M.: Adamantinoma of the long bones. In Bone and Soft Tissue Tumors, pp. 629-638. New York, Springer, 1990.

Changus, G. W.; Speed, J. S.; and Stewart, F. W.: Malignant angioblastoma of bone. A reappraisal of adamantinoma of long bone. Cancer,20: 540-559 1957.20 1957

Chao, E. Y.: A composite fixation principle for modular segmental defect replacement (SDR) prostheses. Orthop. Clin. North America,20: 439-453 1989.20 1989

Czerniak, B.; Rojas-Corona, R. R.; and Dorfman, H. D.: Morphologic diversity of long bone adamantinoma. The concept of differentiated (regressing) adamantinoma and its relationship to osteofibrous dysplasia. Cancer,64: 2319-2334 1989.64 1989

Eisenstein, W., and Pitcock, J. A.: Adamantinoma of the tibia. An eccrine carcinoma. Arch. Pathol. and Lab. Med.,108: 246-250 1984.108 1984

Elliott, G. B.:: Malignant angioblastoma of long bone. So-called "tibial adamantinoma.". J. Bone and Joint Surg.,44-B(1): 25-33 1962.44-B(1) 1962

Enneking, W. F.; Spanier, S. S.; and Goodman, M. A.: Current concepts review. The surgical staging of musculoskeletal sarcoma. J. Bone and Joint Surg.,62-A: 1027-1030, Sept 1980.62-A1027 1980

Gebhardt, M. C.; Lord, F. C.; Rosenberg, A. E.; and Mankin, H. J.: The treatment of adamantinoma of the tibia by wide resection and allograft bone transplantation. J. Bone and Joint Surg.,69-A: 1177-1188, Oct 1987.69-A1177 1987

Gebhardt, M. C.; Jaffe, K. A.; and Mankin, H. J.: Bone allografts for tumors and other reconstructions in children. In Limb Salvage. Major Reconstructions in Oncologic and Nontumoral Conditions, pp. 561-572. Edited by F. Langlais and B. Tomeno. New York, Springer, 1991.

Hazelbag, H. M.; Fleuren, G. J.; van den Broek, L. J.; Taminiau, A. H.; and Hogendoorn, P. C.: Adamantinoma of the long bones: keratin subclass immunoreactivity pattern with reference to its histogenesis. Am. J. Surg. Pathol.,17: 1225-1233, 1993.171225 1993 [PubMed]

Hazelbag, H. M.; Taminiau, A. H. M.; Fleuren, G. J.; and Hogendoorn, P. C. W.: Adamantinoma of the long bones. A clinicopathological study of thirty-two patients with emphasis on histological subtype, precursor lesion, and biological behavior. J. Bone and Joint Surg.,76-A: 1482-1499, Oct 1994.76-A1482 1994

Hazelbag, H. M.; Fleuren, G. J.; Cornelisse, C. J.; van den Broek, L. J.; Taminiau, A. H.; and Hogendoorn, P. C.: DNA aberrations in the epithelial cell component of adamantinoma of long bones. Am. J. Pathol.,147: 1770-1779, 1995.1471770 1995 [PubMed]

Hazelbag, H. M.; Wessels, J. W.; Mollevangers, P.; van den Berg, E.; Molenaar, W. M.; and Hogendoorn, P. C.: Cytogenetic analysis of adamantinoma of long bones: further indications for a common histogenesis with osteofibrous dysplasia. Cancer Genet. and Cytogenet.,97: 5-11, 1997.975 1997

Hicks, J. D.: Synovial sarcoma of the tibia. J. Pathol. and Bacteriol.,67: 151-161, 1954.67151 1954

Huvos, A. G., and Marcove, R. C.: Adamantinoma of long bones. A clinicopathological study of fourteen cases with vascular origin suggested. J. Bone and Joint Surg.,57-A: 148-154, March 1975.57-A148 1975

Ishida, T.; Iijima, T.; Kikuchi, F.; Kitagawa, T.; Tanida, T.; Imamura, T.; and Machinami, R.: A clinicopathological and immunohistochemical study of osteofibrous dysplasia, differentiated adamantinoma, and adamantinoma of long bones. Skel. Radiol.,21: 493-502, 1992.21493 1992

Keeney, G. L.; Unni, K. K.; Beabout, J. W.;, and Pritchard, D. J.:: Adamantinoma of long bones. A clinicopathologic study of 85 cases. Cancer,64: 730-737, 1989.64730 1989 [PubMed]

Knapp, R. H.; Wick, M. R.; Scheithauer, B. W.; and Unni, K. K.: Adamantinoma of bone. An electron microscopic and immunohistochemical study. Virchows Arch. pathol. Anat.,398: 75-86, 1982.39875 1982

Lauche, A.: Zur Kenntnis von Pathologie und Klinik der Geschwï¿½ mit synovialmembranartigem Bau (Synovialome, odev synoviale Endothelio-Fibrome und -Sarkome). Frankfurter Zeitschr. Pathol.,59: 2-29, 1947.592 1947

Lederer, H., and Sinclair, A. J.: Malignant synovioma simulating "adamantinoma of the tibia.". J. Pathol. and Bacteriol.,67: 163-168, 1954.67163 1954

Llombart-Bosch, A., and Ortuno-Pacheco, G.: Ultrastructural findings supporting the angioblastic nature of the so-called adamantinoma of the tibia. Histopathology,2: 189-200, 1978.2189 1978 [PubMed]

Lokich, J.: Metastatic adamantinoma of bone to lung? A case report of the natural history and the use of chemotherapy and radiation therapy. Am. J. Clin. Oncol.,17: 157-159, 1994.17157 1994 [PubMed]

Makley, J. T.: The use of allografts to reconstruct intercalary defects of long bones. Clin. Orthop.,197: 58-75, 1985.19758 1985 [PubMed]

Mandahl, N.; Heim, S.; Rydholm, A.; Willen, H.; and Mitelman, F.: Structural chromosome aberrations in an adamantinoma. Cancer Genet. and Cytogenet.,42: 187-190, 1989.42187 1989

Mankin, H. J.; Doppelt, S. H.; Sullivan, T. R.; and Tomford, W. W.: Osteoarticular and intercalary allograft transplantation in the management of malignant tumors of bone. Cancer,50: 613-630, 1982.50613 1982 [PubMed]

Mirra, J. M.: Adamantinoma and osteofibrous dysplasia. In Bone Tumors. Clinical, Radiologic, and Pathologic Correlations, pp. 1204-1231. Philadelphia, Lea and Febiger, 1989.

Mnaymneh, W., and Malinin, T.: Massive allografts in surgery of bone tumors. Orthop. Clin. North America,20: 455-467, 1989.20455 1989

Moon, N. F., and Mori, H.: Adamantinoma of the appendicular skeleton - updated. Clin. Orthop.,204: 215-237, 1986.204215 1986 [PubMed]

Mori, H.; Yamamoto, S.; Hiramatsu, K.; Miura, T.; and Moon, N. F.: Adamantinoma of the tibia. Ultrastructural and immunohistochemical study with reference to histogenesis. Clin. Orthop.,190: 299-310, 1984.190299 1984 [PubMed]

Ortiz-Cruz, E.; Gebhardt, M. C.; Jennings, L. C.; Springfield, D. S.; and Mankin, H. J.: The results of transplantation of intercalary allografts after resection of tumors. J. Bone and Joint Surg.,79-A: 97-106, Jan 1997.79-A97 1997

Ottolenghi, C. E.:: Massive osteo and osteo-articular bone grafts. Technic and result of 62 cases. Clin. Orthop.,87: 156-164, 1972.87156 1972 [PubMed]

Parrish, F. F.: Allograft replacement of all or part of the end of a long bone following excision of a tumor. Report of twenty-one cases. J. Bone and Joint Surg.,55-A: 1-22, Jan 1973.55-A1 1973

Quill, G.; Gitelis, S.; Morton, T.; and Piasecki, P.: Complications associated with limb salvage for extremity sarcomas and their management. Clin. Orthop.,260: 240-250, 1990.260240 1990

Rock, M. G.; Beabout, J. W.; Unni, K. K.; and Sim, F. H.: Adamantinoma. Orthopedics,6: 472-477, 1983.6472 1983

Rosai, J.: Adamantinoma of the tibia. Electron microscopic evidence of its epithelial origin. Am. J. Clin. Pathol.,51: 786-792, 1969.51786 1969 [PubMed]

Rosai, J., and Pinkus, G. S.: Immunohistochemical demonstration of epithelial differentiation in adamantinoma of the tibia. Am. J. Surg. Pathol.,6: 427-434, 1982.6427 1982 [PubMed]

Schajowicz, F.; Ackerman, L. V.; and Sissons, H. A.: Histological Typing of Bone Tumors. International Histological Classification of Tumors, no. 6. Geneva, World Health Organization, 1972.

Sozzi, G.; Miozzo, M.; Di Palma, S.; Minelli, A.; Calderone, C.; Danesino, C.; Pastorino, U.; Pierotti, M. A.; and Della Porta, G.: Involvement of the region 13q14 in a patient with adamantinoma of the long bones. Human Genet.,85: 513-515, 1990.85513 1990

Springfield, D. S.; Rosenberg, A. E.; Mankin, H. J.; and Mindell, E. R.: Relationship between osteofibrous dysplasia and adamantinoma. Clin. Orthop.,309: 234-244, 1994.309234 1994 [PubMed]

Stauffer, R. N.: Problems with using metallic implants for replacement of bony defects. In Bone and Cartilage Allografts, pp. 295-299. Edited by G. E. Friedlaender and V. M. Goldberg. Park Ridge, Illinois, American Academy of Orthopaedic Surgeons, 1991.

Taylor, G. I.: The current status of free vascularized bone grafts. Clin. Plast. Surg.,10: 185-209, 1983.10185 1983 [PubMed]

Unni, K. K.; Dahlin, D. C.; Beabout, J. W.; and Ivins, J. C.: Adamantinomas of long bones. Cancer,,34: 1796-1805, 1974.341796 1974

VanderWilde, R. S., and Pritchard, D. J.: Adamantinoma of the tibia. Orthopedics,15: 950-953, 1992.15950 1992 [PubMed]

Weiland, A. J.; Moore, J. R.; and Daniel, R. K.: Vascularized bone autografts. Experience with 41 cases. Clin. Orthop.,174: 87-95, 1983.17487 1983 [PubMed]

Weiss, S. W., and Dorfman, H. D.: Adamantinoma of long bones. An analysis of nine new cases with emphasis on metastasizing lesions and fibrous dysplasia-like changes. Human Pathol.,8: 141-153, 1977.8141 1977

Yoneyama, T.; Winter, W. G.; and Milsow, L.: Tibial adamantinoma: its histogenesis from ultrastructural studies. Cancer,40: 1138-1142, 1977.401138 1977 [PubMed]

Topics

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-B: Lateral radiograph showing cortical involvement.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-C:: Computed axial tomography image through the lesion, showing the intracompartmental nature of the tumor.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-D:: Coronal T2-weighted magnetic resonance image through the lesion, showing high signal intensity.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-E:: Plain radiograph and photograph of the specimen after en bloc excision.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2-A:: Figs. 2-A, 2-B, and 2-C: A patient with a biopsy-proved adamantinoma involving the entire tibial diaphysis.
Fig. 2-A: Anteroposterior radiograph showing the lesion.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2-B: Lateral radiograph showing extensive cortical and medullary involvement.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2-C: Radiograph made five years after en bloc tumor resection followed by reconstruction with use of a vascularized graft from the contralateral fibula.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3-B: Anteroposterior radiograph made after removal of the external fixator. Note the union at the proximal and distal graft sites.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 4:: Kaplan-Meier curve showing the proportion of patients with local recurrence (y axis) versus the months from surgery to local recurrence (x axis).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 6:: Kaplan-Meier curve showing the proportion of surviving patients (y axis) versus the years from diagnosis to death or last follow-up (x axis).

View Larger

Table I: Demographic and Clinical Characteristics of Patients with Adamantinoma of a Long Bone

Variable
Age at diagnosis (n = 69) (yrs.)
Mean and standard deviation	31.3 17.6
Median (range)	29 (7-86)
Female gender (n = 70) (no. of patients)	28 (40%)
Prior biopsy (n = 53) (no. of patients)	36 (68%)
Prior diagnosis (n = 67) (no. of patients)
None	41 (61%)
Fibrous dysplasia	9 (13%)
Ossifying fibroma	6 (9%)
Osteofibrous dysplasia	3 (4%)
Epithelioid neoplasm	1 (1%)
Squamous-cell carcinoma	1 (1%)
Spindle-cell carcinoma	1 (1%)
Metastatic adenocarcinoma	1 (1%)
Nonossifying fibroma	1 (1%)
Aneurysmal bone cyst	1 (1%)
Osteomyelitis	1 (1%)
Campanacci disease	1 (1%)
Duration of symptoms (n = 60) (mos.)
Mean and standard deviation	62.5 96.0
Median (range)	24 (0.5-444)
Pathological fracture (n = 70) (no. of patients)	17 (24%)
Tumor site (n = 70) (no. of patients)
Tibia	60 (86%)
Fibula	3 (4%)
Tibia and fibula	4 (6%)
Femur	1 (1%)
Ulna	1 (1%)
Radius	1 (1%)
Enneking stage¹⁰ (n = 69) (no. of patients)
IA	35 (51%)
IB	32 (46%)
III	2 (3%)

Add to My JBJS

Table I: Demographic and Clinical Characteristics of Patients with Adamantinoma of a Long Bone

Variable
Age at diagnosis (n = 69) (yrs.)
Mean and standard deviation	31.3 17.6
Median (range)	29 (7-86)
Female gender (n = 70) (no. of patients)	28 (40%)
Prior biopsy (n = 53) (no. of patients)	36 (68%)
Prior diagnosis (n = 67) (no. of patients)
None	41 (61%)
Fibrous dysplasia	9 (13%)
Ossifying fibroma	6 (9%)
Osteofibrous dysplasia	3 (4%)
Epithelioid neoplasm	1 (1%)
Squamous-cell carcinoma	1 (1%)
Spindle-cell carcinoma	1 (1%)
Metastatic adenocarcinoma	1 (1%)
Nonossifying fibroma	1 (1%)
Aneurysmal bone cyst	1 (1%)
Osteomyelitis	1 (1%)
Campanacci disease	1 (1%)
Duration of symptoms (n = 60) (mos.)
Mean and standard deviation	62.5 96.0
Median (range)	24 (0.5-444)
Pathological fracture (n = 70) (no. of patients)	17 (24%)
Tumor site (n = 70) (no. of patients)
Tibia	60 (86%)
Fibula	3 (4%)
Tibia and fibula	4 (6%)
Femur	1 (1%)
Ulna	1 (1%)
Radius	1 (1%)
Enneking stage¹⁰ (n = 69) (no. of patients)
IA	35 (51%)
IB	32 (46%)
III	2 (3%)

View Larger

Table II: Treatment of Patients with Adamantinoma of a Long Bone

Variable
Biopsy type (n = 69) (no. of patients)
Open incisional	42 (61%)
Open excisional	25 (36%)
Open incisional and closed needle	1 (1%)
Closed needle	1 (1%)
Treatment of tumor (n = 70) (no. of patients)
Initial amputation	6 (9%)
Limb salvage not followed by amputation	59 (84%)
Limb salvage followed by amputation	5 (7%)
Limb salvage type (n = 64) (no. of patients)
En bloc resection	61 (95%)
Intralesional excision	3 (5%)
Amount of bone resected (n = 48) (cm)
Mean and standard deviation	15.3 6.5
Median (range)	14.2 (5-32)
Wide surgical margins (n = 63) (no. of patients)	58 (92%)
Reconstruction type (n = 64) (no. of patients)
Nonvascularized autogenous	19 (30%)
Vascularized fibular	16 (25%)
Allograft	39 (61%)
Ankle arthrodesis (n = 64) (no. of patients)	3 (5%)
Adjuvant treatment (n = 70) (no. of patients)
None	65 (93%)
Radiation only	2 (3%)
Chemotherapy only	2 (3%)
Radiation and chemotherapy	1 (1%)

Add to My JBJS

Table II: Treatment of Patients with Adamantinoma of a Long Bone

Variable
Biopsy type (n = 69) (no. of patients)
Open incisional	42 (61%)
Open excisional	25 (36%)
Open incisional and closed needle	1 (1%)
Closed needle	1 (1%)
Treatment of tumor (n = 70) (no. of patients)
Initial amputation	6 (9%)
Limb salvage not followed by amputation	59 (84%)
Limb salvage followed by amputation	5 (7%)
Limb salvage type (n = 64) (no. of patients)
En bloc resection	61 (95%)
Intralesional excision	3 (5%)
Amount of bone resected (n = 48) (cm)
Mean and standard deviation	15.3 6.5
Median (range)	14.2 (5-32)
Wide surgical margins (n = 63) (no. of patients)	58 (92%)
Reconstruction type (n = 64) (no. of patients)
Nonvascularized autogenous	19 (30%)
Vascularized fibular	16 (25%)
Allograft	39 (61%)
Ankle arthrodesis (n = 64) (no. of patients)	3 (5%)
Adjuvant treatment (n = 70) (no. of patients)
None	65 (93%)
Radiation only	2 (3%)
Chemotherapy only	2 (3%)
Radiation and chemotherapy	1 (1%)

View Larger

Table III: Reconstruction-Related Complications in Patients with Adamantinoma of a Long Bone*

*The sum of the sample sizes for the different types of reconstruction is greater than seventy because more than one type was used for some patients.

Complication	No. of Patients
All reconstructions (n = 62)
None	32 (52%)
Nonunion	15 (24%)
Fracture	14 (23%)
Infection	6 (10%)
Soft-tissue complication	2 (3%)
Delayed union	2 (3%)
Other	7 (11%)
Reconstructions with allograft (n = 38)
None	20 (53%)
Nonunion	6 (16%)
Fracture	8 (21%)
Infection	2 (5%)
Soft-tissue complication	1 (3%)
Delayed union	1 (3%)
Other	6 (16%)
Reconstructions with vascularized fibular graft (n = 16)
None	8 (50%)
Nonunion	5 (31%)
Fracture	3 (19%)
Infection	3 (19%)
Soft-tissue complication	1 (6%)
Delayed union	0 (0%)
Other	2 (13%)
Reconstructions with nonvascularized autograft (n = 19)
None	11 (58%)
Nonunion	5 (26%)
Fracture	3 (16%)
Infection	4 (21%)
Soft-tissue complication	2 (11%)
Delayed union	0 (0%)
Other	2 (11%)

Add to My JBJS

Table III: Reconstruction-Related Complications in Patients with Adamantinoma of a Long Bone*

*The sum of the sample sizes for the different types of reconstruction is greater than seventy because more than one type was used for some patients.

Complication	No. of Patients
All reconstructions (n = 62)
None	32 (52%)
Nonunion	15 (24%)
Fracture	14 (23%)
Infection	6 (10%)
Soft-tissue complication	2 (3%)
Delayed union	2 (3%)
Other	7 (11%)
Reconstructions with allograft (n = 38)
None	20 (53%)
Nonunion	6 (16%)
Fracture	8 (21%)
Infection	2 (5%)
Soft-tissue complication	1 (3%)
Delayed union	1 (3%)
Other	6 (16%)
Reconstructions with vascularized fibular graft (n = 16)
None	8 (50%)
Nonunion	5 (31%)
Fracture	3 (19%)
Infection	3 (19%)
Soft-tissue complication	1 (6%)
Delayed union	0 (0%)
Other	2 (13%)
Reconstructions with nonvascularized autograft (n = 19)
None	11 (58%)
Nonunion	5 (26%)
Fracture	3 (16%)
Infection	4 (21%)
Soft-tissue complication	2 (11%)
Delayed union	0 (0%)
Other	2 (11%)